In a telecommunication service, call information generated when a user uses the telecommunication service is processed into a CDR (call detail record) by an exchange installed in a network. Settlement of a communication charge that occurs as a result of the use of the telecommunication service is performed on the basis of the CDR information.
The volume of the CDR (or call information) generated is significantly influenced by a local characteristic that depends upon the areas where the CDR is generated, including urban areas, suburban areas, and local city areas; or a temporal characteristic closely related to human activity hours or economic activity hours.
Accordingly, the processing efficiency of a billing system for carrying out settlement processing of communication charges on the basis of CDR information deteriorates if the aforesaid local characteristic or temporal characteristic is not taken into account when carrying out such processing.
Furthermore, in the billing system that carries out the settlement processing of communication charges on the basis of the CDR information, if, for example, an exchange system that processes the CDR incurs failure, then the processing of the CDRs involved in the settlement processing is interrupted in the billing system. When the failure is removed thereafter, the CDRs that would have been processed during the period of interruption from the failure are processed all at once and flow into the billing system, thus considerably influencing the settlement processing of communication charges. Hence, the processing efficiency deteriorates unless settlement processing of communication charges is carried out according to the operating condition of the exchange system.